It looks like the nature of this problem is scalar, so you'd need one that naturally applies to a different rank. For instance, we may want to find the locations of the (first instance of) smallest and largest number in a vector of numbers. This naturally applies to a vector (one-dimensional array) and returns a vector.
So, we find the largest number by ">./" and look it up with "i." - combining these gives us the tacit expression "]i.>./" . Finding the smallest has the same form but uses "<." instead of ">.". Combining the two results, specifying we want to work on 1-D sub-arrays, naming and testing this might give us something like this: whereHiLo=: ((]i.>./),(]i.<./))"1 NB. Excess parens are whereHiLo NB. dropped from the definition ((] i. >./) , ] i. <./)"1 whereHiLo i.10 9 0 whereHiLo |.i.10 0 9 whereHiLo 5 6 7 _1 3 4 5 99 1 2 3 7 3 On Sat, Jun 1, 2013 at 12:46 PM, Olivier N. < [email protected]> wrote: > Thanks for this tip! > > I'm fairly new to J and didn't know how to deal with this > and I discovered the &> just a few days ago, thanks to Arie. > > Could you explain to me how I could've written my verb > so it could work with non scalar inputs? > > Regards, > > Olivier > > On 06/01/2013 05:24 PM, Devon McCormick wrote: > > I notice you apply your solution, using &> to each item of your > > (simple=unenclosed) input and return a single scalar for each scalar > > input. It occurs to me that your definition could be more descriptive if > > you made its scalar orientation explicit. That is, you could change the > > first line of your definition to read > > > > tricnt =: 3 : 0"0 > > > > so that you could apply it more simply, e.g. > > > > tricnt 54+i.6 > > > > The above definition form is also helpful to those of us reading your > code > > by alerting us that you expect a scalar input. > > > > Regards, > > > > Devon > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Devon McCormick, CFA ^me^ at acm. org is my preferred e-mail ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
